[S390] dasd: do path verification for paths added at runtime
When a new path is added at runtime, the CIO layer will call the drivers
path_event callback. The DASD device driver uses this callback to trigger
a path verification for the new path. The driver will use only those
paths for I/O, which have been successfully verified.
Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 605f96f..8f2067b 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -913,6 +913,11 @@
cqr->startclk = get_clock();
cqr->starttime = jiffies;
cqr->retries--;
+ if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
+ cqr->lpm &= device->path_data.opm;
+ if (!cqr->lpm)
+ cqr->lpm = device->path_data.opm;
+ }
if (cqr->cpmode == 1) {
rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
(long) cqr, cqr->lpm);
@@ -925,35 +930,53 @@
cqr->status = DASD_CQR_IN_IO;
break;
case -EBUSY:
- DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
+ DBF_DEV_EVENT(DBF_WARNING, device, "%s",
"start_IO: device busy, retry later");
break;
case -ETIMEDOUT:
- DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
+ DBF_DEV_EVENT(DBF_WARNING, device, "%s",
"start_IO: request timeout, retry later");
break;
case -EACCES:
- /* -EACCES indicates that the request used only a
- * subset of the available pathes and all these
- * pathes are gone.
- * Do a retry with all available pathes.
+ /* -EACCES indicates that the request used only a subset of the
+ * available paths and all these paths are gone. If the lpm of
+ * this request was only a subset of the opm (e.g. the ppm) then
+ * we just do a retry with all available paths.
+ * If we already use the full opm, something is amiss, and we
+ * need a full path verification.
*/
- cqr->lpm = LPM_ANYPATH;
- DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
- "start_IO: selected pathes gone,"
- " retry on all pathes");
+ if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
+ DBF_DEV_EVENT(DBF_WARNING, device,
+ "start_IO: selected paths gone (%x)",
+ cqr->lpm);
+ } else if (cqr->lpm != device->path_data.opm) {
+ cqr->lpm = device->path_data.opm;
+ DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
+ "start_IO: selected paths gone,"
+ " retry on all paths");
+ } else {
+ DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+ "start_IO: all paths in opm gone,"
+ " do path verification");
+ dasd_generic_last_path_gone(device);
+ device->path_data.opm = 0;
+ device->path_data.ppm = 0;
+ device->path_data.npm = 0;
+ device->path_data.tbvpm =
+ ccw_device_get_path_mask(device->cdev);
+ }
break;
case -ENODEV:
- DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
+ DBF_DEV_EVENT(DBF_WARNING, device, "%s",
"start_IO: -ENODEV device gone, retry");
break;
case -EIO:
- DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
+ DBF_DEV_EVENT(DBF_WARNING, device, "%s",
"start_IO: -EIO device gone, retry");
break;
case -EINVAL:
/* most likely caused in power management context */
- DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
+ DBF_DEV_EVENT(DBF_WARNING, device, "%s",
"start_IO: -EINVAL device currently "
"not accessible");
break;
@@ -1175,12 +1198,13 @@
*/
if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
cqr->retries > 0) {
- if (cqr->lpm == LPM_ANYPATH)
+ if (cqr->lpm == device->path_data.opm)
DBF_DEV_EVENT(DBF_DEBUG, device,
"default ERP in fastpath "
"(%i retries left)",
cqr->retries);
- cqr->lpm = LPM_ANYPATH;
+ if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
+ cqr->lpm = device->path_data.opm;
cqr->status = DASD_CQR_QUEUED;
next = cqr;
} else
@@ -1364,8 +1388,14 @@
cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
if (cqr->status != DASD_CQR_QUEUED)
return;
- /* when device is stopped, return request to previous layer */
- if (device->stopped) {
+ /* when device is stopped, return request to previous layer
+ * exception: only the disconnect or unresumed bits are set and the
+ * cqr is a path verification request
+ */
+ if (device->stopped &&
+ !(!(device->stopped & ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM))
+ && test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))) {
+ cqr->intrc = -EAGAIN;
cqr->status = DASD_CQR_CLEARED;
dasd_schedule_device_bh(device);
return;
@@ -1381,6 +1411,23 @@
dasd_device_set_timer(device, 50);
}
+static void __dasd_device_check_path_events(struct dasd_device *device)
+{
+ int rc;
+
+ if (device->path_data.tbvpm) {
+ if (device->stopped & ~(DASD_STOPPED_DC_WAIT |
+ DASD_UNRESUMED_PM))
+ return;
+ rc = device->discipline->verify_path(
+ device, device->path_data.tbvpm);
+ if (rc)
+ dasd_device_set_timer(device, 50);
+ else
+ device->path_data.tbvpm = 0;
+ }
+};
+
/*
* Go through all request on the dasd_device request queue,
* terminate them on the cdev if necessary, and return them to the
@@ -1455,6 +1502,7 @@
__dasd_device_check_expire(device);
/* find final requests on ccw queue */
__dasd_device_process_ccw_queue(device, &final_queue);
+ __dasd_device_check_path_events(device);
spin_unlock_irq(get_ccwdev_lock(device->cdev));
/* Now call the callback function of requests with final status */
__dasd_device_process_final_queue(device, &final_queue);
@@ -2586,10 +2634,53 @@
return 0;
}
+int dasd_generic_last_path_gone(struct dasd_device *device)
+{
+ struct dasd_ccw_req *cqr;
+
+ dev_warn(&device->cdev->dev, "No operational channel path is left "
+ "for the device\n");
+ DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
+ /* First of all call extended error reporting. */
+ dasd_eer_write(device, NULL, DASD_EER_NOPATH);
+
+ if (device->state < DASD_STATE_BASIC)
+ return 0;
+ /* Device is active. We want to keep it. */
+ list_for_each_entry(cqr, &device->ccw_queue, devlist)
+ if ((cqr->status == DASD_CQR_IN_IO) ||
+ (cqr->status == DASD_CQR_CLEAR_PENDING)) {
+ cqr->status = DASD_CQR_QUEUED;
+ cqr->retries++;
+ }
+ dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
+ dasd_device_clear_timer(device);
+ dasd_schedule_device_bh(device);
+ return 1;
+}
+EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
+
+int dasd_generic_path_operational(struct dasd_device *device)
+{
+ dev_info(&device->cdev->dev, "A channel path to the device has become "
+ "operational\n");
+ DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
+ dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
+ if (device->stopped & DASD_UNRESUMED_PM) {
+ dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
+ dasd_restore_device(device);
+ return 1;
+ }
+ dasd_schedule_device_bh(device);
+ if (device->block)
+ dasd_schedule_block_bh(device->block);
+ return 1;
+}
+EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
+
int dasd_generic_notify(struct ccw_device *cdev, int event)
{
struct dasd_device *device;
- struct dasd_ccw_req *cqr;
int ret;
device = dasd_device_from_cdev_locked(cdev);
@@ -2600,41 +2691,64 @@
case CIO_GONE:
case CIO_BOXED:
case CIO_NO_PATH:
- /* First of all call extended error reporting. */
- dasd_eer_write(device, NULL, DASD_EER_NOPATH);
-
- if (device->state < DASD_STATE_BASIC)
- break;
- /* Device is active. We want to keep it. */
- list_for_each_entry(cqr, &device->ccw_queue, devlist)
- if (cqr->status == DASD_CQR_IN_IO) {
- cqr->status = DASD_CQR_QUEUED;
- cqr->retries++;
- }
- dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
- dasd_device_clear_timer(device);
- dasd_schedule_device_bh(device);
- ret = 1;
+ device->path_data.opm = 0;
+ device->path_data.ppm = 0;
+ device->path_data.npm = 0;
+ ret = dasd_generic_last_path_gone(device);
break;
case CIO_OPER:
- /* FIXME: add a sanity check. */
- dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
- if (device->stopped & DASD_UNRESUMED_PM) {
- dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
- dasd_restore_device(device);
- ret = 1;
- break;
- }
- dasd_schedule_device_bh(device);
- if (device->block)
- dasd_schedule_block_bh(device->block);
ret = 1;
+ if (device->path_data.opm)
+ ret = dasd_generic_path_operational(device);
break;
}
dasd_put_device(device);
return ret;
}
+void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
+{
+ int chp;
+ __u8 oldopm, eventlpm;
+ struct dasd_device *device;
+
+ device = dasd_device_from_cdev_locked(cdev);
+ if (IS_ERR(device))
+ return;
+ for (chp = 0; chp < 8; chp++) {
+ eventlpm = 0x80 >> chp;
+ if (path_event[chp] & PE_PATH_GONE) {
+ oldopm = device->path_data.opm;
+ device->path_data.opm &= ~eventlpm;
+ device->path_data.ppm &= ~eventlpm;
+ device->path_data.npm &= ~eventlpm;
+ if (oldopm && !device->path_data.opm)
+ dasd_generic_last_path_gone(device);
+ }
+ if (path_event[chp] & PE_PATH_AVAILABLE) {
+ device->path_data.opm &= ~eventlpm;
+ device->path_data.ppm &= ~eventlpm;
+ device->path_data.npm &= ~eventlpm;
+ device->path_data.tbvpm |= eventlpm;
+ dasd_schedule_device_bh(device);
+ }
+ }
+ dasd_put_device(device);
+}
+EXPORT_SYMBOL_GPL(dasd_generic_path_event);
+
+int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
+{
+ if (!device->path_data.opm && lpm) {
+ device->path_data.opm = lpm;
+ dasd_generic_path_operational(device);
+ } else
+ device->path_data.opm |= lpm;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
+
+
int dasd_generic_pm_freeze(struct ccw_device *cdev)
{
struct dasd_ccw_req *cqr, *n;